Original subtitles

Imagine you're cast at birth into a galaxy of tiny drifting creatures.

A speck lost in the ocean.

You never met your mother or father.

You have no one to show you where to go or what to do.

That's how life begins for this little sharpnose pufferfish.

We'll call him Puff.

Just a couple of months old, he's smaller than a fingernail.

Adrift in the ocean, headed for an uncertain future.

This is Puff's world.

A vibrant coral reef, home to thousands of creatures.

But to see what Puff sees, you have to look closer.

Even closer.

Because the story of every coral reef starts with its tiniest creatures.

For the first time, we have opened a window to their incredible micro-verse.

A world where drama unfolds on scales too small...

too fast...

or too slow for the human eye to perceive.

And from Puff's tiny point of view,

it must seem almost magical.

The reef as we've never seen it before.

To the naked eye, the open ocean may seem lifeless,

but when you look closer, billions of tiny creatures are revealed.

Some so minute that hundreds of individuals

would fit in a single drop of water.

This is where Puff begins his life journey.

He hatched from an egg on the reef and drifted with the current out to sea,

to feed on tiny plankton.

This is how many reef fish begin their lives.

But within months,

these microscopic morsels are no longer enough to sustain him.

He needs to find bigger things to eat.

And that poses a problem as big as the ocean.

How will Puff find his way back to the reef?

Something amazing happens when lots of creatures gather in the same place.

Crowds make noise,

and a coral reef is a busy place.

Sound can travel for miles underwater.

All Puff has to do is listen.

Most of what you see here is built by animals

smaller than the tip of your finger.

Thousands of lives and millions of stories are unfolding.

Don't believe me?

Try looking from Puff's perspective.

The smallest of these animals are no larger than a grain of sand.

Puff's new world is a micro-verse of tiny creatures

that live their lives unnoticed by giants like us.

At around three months of age, Puff is only the size of a jellybean.

That's not just daunting,

it's dangerous.

Fortunately for Puff, he has an ingenious way of defending himself.

He's toxic.

And he comes with a warning label.

The markings on his body say,

"Eat me, and you'll regret it."

But being poisonous doesn't make him invincible.

And nearby, a predator lurks.

A lionfish.

This ferocious hunter's dazzling fins

are perfect for herding small prey into tight spots.

Most young reef fish don't survive their first year of life.

Luckily for Puff,

the coral creates a maze of tiny passageways

where a baby fish can hide for the night.

Out of sight,

and off the menu.

As Puff sleeps, the foundations of his world begin to stir.

Every year,

the moon, the tides, and the water temperature

all signal to billions of corals

that tonight is the night to cast the young to the sea.

At the mouths of tiny coral polyps,

minuscule bundles of eggs and sperm appear.

In near perfect synchronicity, they lift off...

and journey to the surface.

The bundles drift with the current and mix with the spawn

of thousands of other coral colonies.

If among the billions of eggs released tonight

one should meet its match...

something extraordinary happens.

A microscopic larva forms,

a barely visible creature on a quest to build a new coral colony.

It drifts for days

until it hears the call of the reef.

And dives,

braving a minefield of predators and traps.

When you're the size of a speck,

a three-centimeter-long shrimp can be monstrous.

On the reef, the larva searches for a perfect place to make its home.

When it finds the right spot,

it transforms

from a free-swimming larva into a young coral.

As it grows, its skeleton forms part of the reef.

With the help of other tiny construction workers,

the corals build living structures

that create homes for countless other creatures.

It takes hundreds, sometimes thousands of years,

for generations of tiny reef-builders to construct Puff's coral metropolis.

Inside his reef hiding place, Puff is safe for now.

But he needs to brave the predators and head out to find food.

And once again, the corals help out.

Because corals produce energy that feeds the animals of the reef.

It all starts with single-celled, plant-like creatures

living within the corals, the zooxanthellae.

Don't let that big name fool you.

Everything here, really small.

These little guys are the coral's life partners,

harvesting energy from sunlight to feed their coral hosts.

And as the corals grow and thrive,

they share their energy with the rest of the reef.

Some creatures consume the energy directly by eating the coral.

This baby crown-of-thorns starfish

uses tiny eyespots on the end of each arm to locate coral colonies.

A keen sense of underwater smell helps it find the right species.

And it devours the coral polyps, leaving a scar on the reef.

Not all inhabitants feed on the coral directly.

If they did, they'd soon demolish their reef city.

Fortunately, there's another way corals supply food.

They do it with slime.

Corals shed mucus too fine for creatures like Puff to eat,

but an ancient group of organisms makes sure this energy is not lost.

Sponges.

To the naked eye, they may appear motionless,

but if you speed up time, their vital role in the reef is revealed.

Sponges pump huge volumes of water through their bodies,

filtering out the coral mucus and using the energy to grow.

After they've had their fill,

the sponges concentrate organic waste on their surfaces,

creating a bite-sized buffet

for tiny creatures to feed on.

And those animals are eaten by slightly bigger creatures.

Oh no. No, no, no. Just slightly bigger? No, that's... That's way too big.

That's huge. That's massive.

This... yes.

That's better.

Some of the recycled sponge food also washes up the water column

where it's captured and consumed by filter feeders.

Like the Christmas tree worm.

Easily the most festive worm of the sea.

This almond-sized porcelain crab

uses feathery claws to capture tiny particles of food

from the water.

Down here, every surface is covered with life.

Nothing goes to waste.

On the back of a sea snail the size of an olive,

even smaller creatures make their home.

Without these little creatures recycling the energy captured by the corals,

the larger ones would have nothing to eat.

Life on the reef is dependent on thousands of creatures working together,

each with a vital role to play.

Puff is perfectly adapted to hunt in this tiny world.

But the grim fact is, most things that eat can also be eaten.

Not all corals are harmless.

Some are predators...

their tentacles covered in deadly cells

that harpoon and paralyze speck-sized prey.

If he's going to survive the depths of the reef,

Puff must learn all the secrets of its dark recesses.

Some alleyways are more treacherous than others.

This anglerfish is about as long as your thumb.

A giant in this micro world.

Puff's discovered his pufferfish superpower.

He can blow up like a balloon in a fraction of a second,

a trick that has just saved his life.

Being one of the smallest fish on the reef means Puff is in constant danger.

His superpower may keep predators at bay for a while,

but other forces are beyond his control.

Above the waves, a storm brews in a world that Puff can never know.

Its brutal force delves deep into the ocean.

Despite its abundance of food,

the reef remains a treacherous place for a baby fish.

Instinct tells him there may be safer waters beyond the coral metropolis.

But to find this haven, he must cross a strange, new world.

The sand flats.

Among the sand grains, it's every crab for herself.

The plains are home to creatures that scavenge, sift, and burrow.

Out here, it's a fish-eat-brittle-star world.

In the dunes,

Puff finds a mollusk hauling its shell through a garden of walking dendros.

These walnut-sized corals live on the sand,

absorbing sunlight and feeding on tiny creatures.

But it isn't all sun-baking and snacks.

They're in constant danger of being toppled or buried alive.

A death sentence for a coral that needs sunlight.

But sometimes help comes from unexpected places.

Like, really unexpected places.

In this case, from a wormhole.

The peanut worm lives in a hole in the base of the dendro.

The worm keeps its coral landlord upright.

In return, the dendro offers protection

as its slippery tenant scours the sand for food,

towing its coral caravan along for the ride.

There are no small roles here, only small organisms.

The journey across the sand flats may not be a great distance,

but for a baby fish, it's an odyssey.

Out here, there's nowhere to hide and not much to eat.

Just when it seems like the sand might go on forever,

an oasis appears on the horizon.

A labyrinth of mangrove roots,

pockets and passageways with plenty to eat and fewer ways to be eaten.

The ideal place for a thumbnail-sized fish to feed,

grow, and perfect the skills he'll need to survive.

He's not the only one to have made this pilgrimage.

The shallows are a haven for all kinds of baby reef fish.

Puff has found his fish nursery.

Things are looking up.

It's been days since his last proper meal.

He's so hungry he could eat a horse.

Or maybe not.

But he does need to find food, and fast.

Watching how the locals do it could help him.

Pinky-sized seahorses are expert hunters in this tiny world.

They target crustaceans smaller than a grain of rice.

These tiny grazers spend their time munching on algae

and microscopic animals in the seagrass.

They play an essential role in the food web here.

A link between the plants and larger creatures like Puff.

In the meadows of the lagoon,

algae and seagrasses harvest energy from the sun.

Supplying food for the community

as well as producing oxygen for the rest of the planet.

It's a big job for these tiny plants.

Seagrass flowers are smaller than dandelions.

And they attract swarms of the tiny crustaceans

that Puff and the seahorses love to eat.

Like these, the crustaceans can carry pollen from flower to flower.

The lagoon is a cosmos of worlds within worlds.

The closer you look, the more you find.

On a blade of seagrass,

a microscopic entoproct rolls the contents of its tiny stomach.

Very little is known about this world.

It's just too small.

After six months in the shallows,

Puff is now an adolescent.

And he's eating like one.

He's quadrupled in size.

And his confidence is growing.

But he can't let his guard down.

Even this idyllic nursery has ambush predators.

This scorpion fish is perfectly camouflaged,

waiting for unsuspecting victims to cruise by.

But sometimes, the camouflage can backfire.

The lagoon is a network of relationships.

Everywhere you look, tiny stories are unfolding.

This guard crab doesn't like baby fish taking bites out of his home.

And he's not gonna put up with any trouble from a grape-sized butterfly fish.

Just when he thought his work was done,

a hermit decides to trample his polyps.

And clearly, that's not okay.

A crab might look tough when he's dispatching intruders,

but without his coral refuge, he, too, could end up as someone's dinner.

The crab needs its coral as much as the coral needs its crab.

Every creature is dependent on others for its survival.

Little Puff has grown to the size of a human thumb.

Just over two inches long, and he's finally outgrown this nursery.

Now that he's bigger, the abundant food back at the reef seems more attractive.

He'll have to cross the sand flats again.

But this time, Puff sets out as a young adult

in search of his forever home.

Early into the crossing,

Puff comes across a blind zombie snail sniffing out its next meal.

Tiny scavengers like him are the ocean's clean-up crew.

It's a dirty job, but someone's got to do it.

Nearby, a predatory cone snail is on the hunt.

And he catches the scent of a zombie snail on the current.

A low-speed chase begins.

Like a lion hunting a gazelle on the African plains,

the action is thrilling.

Not really, but it's pretty exciting when you speed it up.

Out here, you can run,

but you can't hide.

Not from a cone snail's highly-developed sense of smell.

The cone snail dispatches the zombie with a venomous harpoon.

Ruthless.

It's a snail-eat-snail world,

but Puff is learning to take all the murder and mayhem in his stride.

And right now, he's more concerned with grabbing fast food

on the long journey back to the reef.

As Puff approaches the reef, he finds a changed world.

Strange colors signal that the corals are suffering.

The water temperature is well above their comfort zone.

Within the corals, the zooxanthellae are stressed,

and the corals start to expel them.

Without their little life partners supplying food,

they begin to bleach and starve.

The corals are dying.

Puff's underwater metropolis, constructed over thousands of years,

is reduced to rubble by a warming ocean.

Many of our planet's coral reefs are already in this catastrophic state.

Every year, the collapse continues.

Unless we change the way we do things in our world,

Puff's world will cease to exist.

This was supposed to be journey's end for Puff,

but he can't stay here.

He'll have to move on in search of a healthy reef to call home.

At around two years of age,

Puff is now ten times longer than when he first arrived on the reef.

About the size of the palm of your hand.

It's that time of year again,

when the cycles of the moon and the temperature of the water

trigger the reproductive systems of billions of corals

on Australia's Great Barrier Reef.

What starts as a trickle soon floods the sea with hope.

A new generation sets off to repair,

restore, and create new coral reefs.

On the same night, thousands of other reef creatures join the mass spawning.

It's the biggest reproductive event on Earth.

With a little luck, some of these microscopic heroes will drift to a place

where the fish are healthy,

the water is clean,

and the temperature is just right.

If they do, they may, against incredible odds,

complete their vital mission...

to build and maintain the largest living structure on Earth.

Puff has finally found his happy place, a healthy coral reef.

Now that he's bigger and more confident,

old enemies that once bullied him steer clear.

Yeah, keep swimming, lionfish.

Just keep swimming.

All grown up, Puff will soon find a territory,

an area he will get to know like the back of his fin.

And he'll defend it from other male pufferfish,

in the hope that someday he might find a mate.

Puff and his mate could live for almost a decade.

One day, their young will be cast into the ocean

to play a vital role in this wonderful ecosystem.

And they'll have some big shoes to fill.

Our window to this micro world has only just opened.

Its tiny creatures are revealing themselves

to be intelligent and complex beyond our imagining.

There are still places to swim with sharpnose pufferfish,

camouflaged monsters, and colorful corals.

These extraordinary little beings are doing all they can

to maintain their fragile world.

The rest is up to us.

♪ What do you feel ♪

♪ I gotta know ♪

♪ I gotta know ♪

♪ Whatever it is ♪

♪ You should let it go ♪

♪ Let it go ♪

♪ Dance when you wanna dance ♪

♪ Sing when you wanna sing ♪

♪ Live how you wanna live ♪

♪ Let yourself be free ♪

♪ Dance when you wanna dance ♪

♪ Sing when you wanna sing ♪

♪ Live how you wanna live ♪

♪ Let yourself be free ♪

♪ Can't nobody ♪

♪ Turn me around ♪

♪ Can't nobody ♪

♪ Slow me down ♪

♪ I got this feeling way down in my soul ♪

♪ Gotta hold of me And it just won't let me go ♪

♪ Dance when you wanna dance ♪

♪ Sing when you wanna sing ♪

♪ Live how you wanna live ♪

♪ Let yourself be free ♪

♪ Dance when you wanna dance ♪

♪ Sing when you wanna sing ♪

♪ Live how you wanna live ♪

♪ Let yourself be free ♪

♪ Dance when you wanna dance ♪

♪ Sing when you wanna sing ♪

♪ Let yourself be free ♪